CN101637056B - Resource allocation in a communication system - Google Patents

Abstract

A method and corresponding system for determining transmit power in a mobile device (108) includes receiving, in the mobile device, a cell-wide power control parameter related to a target received power of a serving base station (104). Thereafter, a transmit power is calculated (608) in response to the cell-wide power control parameter and the implicit mobile-specific power control parameter. The mobile device then transmits using the transmit power (610). The cell-wide power control parameter may be a cell target value for a signal to interference plus noise ratio, or a fractional power control index. The implicit mobile-specific power control parameter may be a modulation and coding level previously used by the mobile device or a downlink SINR level measured by the mobile device.

Description

Resource Allocation in Communication Systems

technical field

The present invention relates generally to communication systems and devices, and more particularly to techniques and apparatus for allocating communication system resources to mobile devices in a communication system.

Background technique

Many wireless communication systems employ a base station to communicate with one or more mobile devices (ie, user equipment, or "UE") within a cell served by the base station. Data transmitted from the base station to the user equipment is transmitted through a wireless channel called a downlink channel, and data transmitted from the user equipment to the base station is transmitted through a wireless channel called an uplink channel.

Wireless communication systems have limited resources that can be allocated to mobile devices and typically attempt to allocate to maximize the use of available bandwidth in uplink and downlink channels. For example, a frequency or set of frequencies is a resource that can be allocated to a mobile device for wireless transmission or reception. The time used for transmission, or transmission "slots," is also a resource that can be allocated to a mobile device for wireless transmission or reception.

With respect to transmissions in the uplink channel, transmit power is the resource that can be allocated to a mobile device for wireless transmission. Proper allocation of transmit power is required so that the base station receives a relatively flat power level across the frequency spectrum used by the mobile devices. Proper transmission power allocation also helps avoid interference from transmissions of other mobile devices, whether these other mobile devices are located in the same cell or in neighboring cells.

The distance between the mobile device and the base station, as well as other types of path loss between the mobile device and the base station, can affect the power received by the base station. Distance-dependent path loss reduces the power of a received signal because of the distance the signal travels. Furthermore, power can be reduced by shadowing, which occurs when an object is present between the mobile device and the base station. For example, if a person with a mobile device is walking on the street and a building appears between the mobile device and the base station, the path loss increases due to shadowing effects.

Description of drawings

The present invention is illustrated by way of example and is not limited by the accompanying drawings, wherein like reference numerals refer to like parts. Components in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale.

Figure 1 is a high-level block diagram of a wireless communication system in accordance with one or more embodiments;

FIG. 2 is a high-level jump diagram depicting messages sent between various components of the wireless communication system of FIG. 1 in accordance with one or more embodiments;

Figure 3 is a representation of a message format according to one or more embodiments;

FIG. 4 is a high-level jump diagram depicting messages sent between various components of the wireless communication system of FIG. 1 in accordance with one or more embodiments;

Figure 5 is a high-level flowchart describing a process that may be performed by a mobile device in accordance with one or more embodiments; and

Figure 6 is a high-level flowchart describing processes that may be performed by a mobile device in accordance with one or more embodiments.

Detailed ways

FIG. 1 is a high-level diagram of portions of a communication system 100 in accordance with one or more embodiments. The communication system 100 may be a wireless communication system or other similar communication system that uses power control techniques and algorithms to control the transmit power of one or more devices transmitting data. As shown, FIG. 1 includes base stations 102 and 104 and mobile devices 106 and 108, which may also be referred to as mobile stations, subscriber units, mobile terminals, or user equipment (UE). Base station 102 typically communicates wirelessly with mobile devices in cell 110 , while base station 104 typically communicates wirelessly with mobile devices in cell 112 . A base station controller 114 (which may be referred to as an eNode-B or evolved Node-B in some embodiments) is coupled to base station 102, and possibly other base stations 116, to control the operation of base station 102 and other base stations. In various embodiments, the base station controller 114 may implement packet scheduling functions, connection mobility control, load balancing, switching between radio access technologies, and the like. Similarly, a base station controller 118 is coupled to base station 104 and possibly to other base stations 120 for purposes of controlling base station 104 . The base station controller can be coupled to the base station via a communication link which may be wireless, wire, fiber optic or the like. In some embodiments, the base station controller may be co-located with the base station.

In one embodiment, the communication system 100 may be implemented in accordance with the specifications of the Long Term Evolution (LTE) project within the Third Generation Partnership Project (3GPP) wireless system, which is essentially capable of transporting voice (e.g., VoIP) and other data wireless packet data system.

Mobile device 106 can communicate with base station 102 via wireless communication link 122 . Mobile device 108 can communicate with base station 104 via wireless communication link 124 . When a mobile device 106 is close to the edge of its serving cell 110, and also close to another mobile device 108 (mobile device 108 is close to the edge of its serving cell 112), interference from the mobile device 108 can interfere with the wireless communication link 122 for transmissions from mobile device 106, particularly when mobile device 106 and mobile device 108 are assigned the same transmission frequency.

In each of cells 110 and 112, a base station (eg, base stations 102 and 104) can simultaneously receive uplink transmissions from multiple mobile devices, such as mobile device 106 and other mobile devices not shown. In some embodiments, the base station is configured to receive wireless uplink transmissions having substantially the same received signal strength. In order to make the received signal strength substantially the same, an uplink transmission power control algorithm may be used to control the transmission power of each mobile device. In one embodiment, a base station may broadcast cell-wide power control parameters to all mobile devices in the cell served by the base station. For example, in one embodiment, the base station 102 may broadcast a cell-wide target value (ie, a power control parameter) of received power related to the signal-to-interference-plus-noise ratio (SINR) received by the base station to the stations served by the base station 102. All mobile devices (eg, mobile device 106).

In another embodiment, the cell-wide power control parameter may be a fractional power control index. The fractional power control index can be expressed as the symbol "α" in Equation 1 as follows:

mobile_station_power _i =Pmax×min(1, max(R _min , (PL _i /PL _xile ) ^α ) (Equation 1)

Among them, mobile_station_power _i is the power calculated by the i-th mobile device in the cell, PL _xile is the x percentile of the path loss from all mobile devices in the cell to the base station, R _min is the minimum power reduction ratio, and PL _i is the path loss from the mobile device (or UE) concerned to the base station. Using Equation 1 above with 0<α<1, mobile devices at the center of the cell have lower thresholds than those at the edge of the cell, resulting in less interference in the network.

Referring now to FIG. 2 , a "jump diagram" for illustrating messages communicated between various components of the communication system 100 is depicted. As shown, messages are communicated between mobile device 202 , serving base station 204 , and base station controller 206 . The base station controller 206 may be implemented according to the base station controller 114 shown in FIG. 1 . Although base station 204 and base station controller 206 are shown separately, they may or may not be physically co-located, depending on various systems.

Before the mobile device is synchronized (e.g., when the mobile device is in idle mode), the mobile device may initiate communication with the serving base station by sending an asynchronous RACH 208 (i.e., an asynchronous random access channel message). The random access channel is usually shared by all mobile devices in the cell served by the base station. The asynchronous RACH 208 preamble can tell the base station 204 that the mobile device 202 has a message for the base station. A request for service on a random access channel may be referred to as a "RACH request."

Asynchronous RACH 208 initially transmits lower power to avoid excessive interference. Therefore, base station 204 may not receive asynchronous RACH 208. If the base station 204 does not receive the asynchronous RACH 208, the base station 204 will not respond and the mobile device 202 will retransmit the asynchronous RACH 210 at incrementally higher power levels so that the base station 204 eventually receives the asynchronous RACH.

Upon receiving the asynchronous RACH 210, the base station 204 may respond by sending a RACH response 212. The RACH response 212 may include a message from the base station 204 that responds to the mobile device 202 and further instructs the mobile device 202 regarding signal timing, transmit power, and time and frequency for the next uplink transmission. As an example, the RACH response 212 may contain instructions to the mobile device 202 to adjust the timing of its transmissions by adding 1.04 μS, adjust the transmit power by decreasing 2 dB, and transmit at a specific starting frequency with a specific number of frequencies and at a specific time Synchronous RACH (ie, synchronous RACH messages) within the interval.

After receiving the RACH response 212, the mobile device 202 can respond with a synchronous RACH message 214 indicating that the mobile device is requesting service from the base station. Additionally, the mobile device 202 can use a portion or segment of the message to indicate that it has a resource usage limit if such resource usage limit exceeds a limit threshold reported to the base station.

In one embodiment, the mobile device resource usage limit can be limited to the number of resource blocks that can be used during an uplink transmission associated with the current power level and the current modulation and coding scheme (MCS). In another embodiment, the mobile device resource usage limit may be the amount of remaining power (eg, power headroom) that can be used for uplink transmission. Thus, in one embodiment, the synchronous RACH message 214 may indicate that the mobile device has a file to be transferred (i.e., requesting a file transfer service), and that the power of the mobile device is limited to 4 resource blocks (i.e., considering the current transmit power, The mobile device's maximum transmit power and current modulation and coding scheme, the mobile device's resource usage constraints indicate that the mobile device should not be assigned more than 4 resource blocks).

Note that the resource usage limit must exceed the limit threshold before the limit is reported to the base station. This limit threshold for reporting should be set at the point where the device resource usage limit is reported when there is a possibility that the uplink scheduler will schedule uplink transmissions that exceed the capacity of the mobile device. When a mobile device sends a mobile device resource usage limit message, the base station (or other uplink traffic scheduling entity) can use this information to intelligently schedule uplink traffic in a manner that does not exceed the transmit power capacity of the mobile device. For example, if the base station 204 decides to allocate a greater number of resource blocks than the mobile device has indicated as a limit, the base station can scale back the modulation and coding scheme accordingly so that the mobile device can transmit on all assigned resource blocks. the requested power.

As for the format of the synchronization RACH message 214, FIG. 3 shows an example of one embodiment of the message format. As shown, message 300 may include header 302 , service request 304 , service request parameters 306 , optional mobile device resource usage limit 308 , and error control field 310 . Header 300 may be used to indicate the type of message. Service Request 304 may be a field used to indicate a request for service from a base station serving a mobile device. Such requests for services may include requests to transfer files, make voice calls, email delivery, download music or video clips, or the like. Service request parameters 306 may contain information related to the service request, such as the file size of the file transfer, or other similar information needed to complete the service request.

If the threshold for reporting a mobile device resource usage limit has been exceeded, the mobile device resource usage limit 308 portion of the synchronous RACH message 214 may include a power limit flag 312 indicating whether the mobile device may be scheduled in excess of its power capacity for uplink communications . For example, if the flag is set, it can indicate that the mobile device is currently operating at close to its maximum power, which means that the base station can schedule uplink transmissions for the mobile device that will exceed its power transmission capacity. If the current power of a transmission is 21dB, and the maximum power transmission is 24dB, then there is a possibility that the base station may use 4 resource blocks to schedule the mobile for the uplink transmission, which is only 3dB of extra power available before the mobile reaches the maximum power may require an additional 6dB of power. In the case where the base station 204 may schedule 4 resource blocks for the mobile device 202, the base station 204 may either limit the maximum number of resource blocks to 2, or the base station 204 may schedule 4 resource blocks and assume that the mobile device 202 will divide by 2 to reduce the transmit power (ie, reduce the power by 1/2) and use all 4 resource blocks. Note that the base station 204 may schedule a number of resource blocks that exceeds the number of resource blocks reported in the mobile device resource usage limit 308 because the mobile device may be a better candidate for scheduling than other mobile devices.

In addition to the power limit flag 312, the mobile device resource usage limit field 308 may include a field 314 indicating resource block capacity. Resource block capacity field 314 may indicate the maximum number of resource blocks that the mobile device can use, or the field may indicate the number of additional blocks that can be used by the mobile device. The current transmit power field 316 may be used to indicate the current transmit power of the mobile device. If the mobile device sends the current transmit power to the base station, the base station can calculate the maximum number of resource blocks that can be used by the mobile device, or the number of additional blocks that can be used by the mobile device. Embodiments of the mobile device resource limit field 308 may include a power limit flag 312 and resource block capacity 314 or current transmit power 316 or both.

Mobile device resource usage restrictions field 308 may also indicate other restrictions of the mobile device. For example, many mobile devices can transmit using one of several different levels of modulation and coding schemes (MCS). If the mobile device does not have all classes, or if some classes are not available because of low battery (or other similar constraints), or because the mobile device is not a full-featured device implementing all MCS classes, then the mobile device resource The scheduler can be informed of these restrictions using the restriction field 308 so that the mobile device is not scheduled to perform uplink transmissions that it cannot complete.

In FIG. 2 , after the mobile device sends the synchronization RACH message 214 to the serving base station 204 , the message is forwarded to the base station controller 206 as shown at 216 . The base station controller 206 can respond with a downlink control message 218 sent to the serving base station 204 and forwarded to the mobile device 202 as shown at 220, wherein the downlink control message instructs the mobile device 202 to sound out at a specific time and frequency. )channel. Mobile device 202 may respond by sending an unlink channel sounding message 222, in which the mobile device transmits known code or data (e.g., already known data sequence). In some embodiments, the known code may be a pilot sequence embedded in the uplink data channel. Channel measurement is the process used to characterize the channel between a base station and a mobile device. The channel can be characterized by computing the channel impulse response.

After the base station 204 has received the uplink channel measurement message 222 , the base station 204 prepares a carrier-to-interference-plus-noise ratio (CINR) and a power control (PC) report 224 , which are then forwarded to the base station controller 206 . CINR is a measure of signal effectiveness expressed in decibels (dB). The carrier is the desired signal, while the interference may include noise, co-channel interference, or other channel interference, or all of them. In order for a signal receiver to decode a signal, the signal must fall within an acceptable CINR range. Co-channel interference is a bigger problem when frequencies are reused over short distances. In embodiments where the system does not use channel measurements, the base station 204 may infer the CINR from long-term tracking of the channel through reference symbols of the data channel.

Upon receipt of any mobile device resource usage constraints, and any mobile-specific power control parameters such as data obtained from channel measurements, base station controller 206 may prepare and send resource allocation grant 226 to base station 204 . The resource allocation grant 226 is then forwarded to the mobile device 202 as shown at 228 .

Resource allocation grant 226 may be either a dynamic resource allocation grant or a persistent resource allocation grant. A dynamic resource allocation grant is a relatively short-term grant that includes a one-time power control instruction for use during the duration of the dynamic resource allocation grant. A persistent resource allocation grant is a longer period grant that includes power control instructions initially used during the dynamic resource allocation grant, and subsequent power control instructions received periodically for the duration of the persistent resource allocation grant.

4 is a hop diagram depicting messages sent between mobile device 202, serving base station 204, and base station controller 206 that result in a persistent resource allocation grant, according to one or more embodiments. Message and data communications 208 to 224 are similar to those steps described above with reference to FIG. 2 . In this example, the synchronous RACH 214 may include a request for base station service most appropriate for a persistent resource allocation grant. For example, a synchronous RACH 214 may include a request for a voice call. Persistent resource allocation grant 402 is sent from base station controller 206 to base station 204 and then forwarded to mobile device 202 as shown at 404 . The persistent resource allocation grant 402 may contain power control instructions initially used during the persistent resource allocation grant. Subsequent power control commands may be sent from base station controller 206 to base station 204 , and mobile device 202 . For example, after a period of time, the persistent resource allocation grant 402 is followed by a reduced power instruction 406 . As shown at 408, the reduce power command 406 is forwarded to the mobile device 202 to instruct the mobile device 202 to reduce its power by a predetermined increment. For the duration of the persistent resource allocation grant, the power control command 406 is followed by additional periodic power control commands 410 and 414 , which are forwarded to the mobile device 202 as shown at 412 and 416 , respectively.

Thus, according to the dynamic resource allocation grant 226 , the mobile device 202 operates in a mode that does not expect additional power control instructions from the base station 204 . According to the persistent resource allocation grant 402, the mobile device 202 operates in a mode that expects additional power control instructions from the base station 204 for the duration of the persistent resource allocation.

FIG. 5 shows a high-level flowchart of processes that may be performed by mobile device 106 in FIG. 1 , or other systems with appropriate functionality, in accordance with one or more embodiments. As shown, the process begins at 502 and thereafter continues at 504, where the process sends an asynchronous RACH to the base station. Asynchronous RACH messages such as asynchronous RACH messages 208, 210 in FIG. 2 may be sent from an idle mobile device (eg, mobile device 106) to a base station (eg, base station 102) to alert the base station that the mobile device has a message for the base station.

Next, the process receives a RACH response from the base station, as indicated at 506 . A RACH response acknowledges the transmission from the mobile device and may further instruct the mobile device to adjust its transmission timing and its transmit power and respond with a synchronized RACH at a specific time slot and specific frequency (eg, frequency set or resource block).

After receiving the RACH response, the mobile device determines a mobile device power limit, as indicated at 508 . In one embodiment, this step may be implemented by determining the power headroom of the mobile device, where the power headroom is the difference between the power indicated by the mobile device in the RACH response and the maximum power of the mobile device.

Once the mobile device's power limit has been determined, the process determines a mobile device resource usage limit based on the power limit, as indicated at 510 . In one embodiment, this step can be implemented by determining the maximum number of resource blocks that the mobile device can use in uplink transmission based on the power headroom. For example, in one embodiment, if a mobile device is currently indicated to transmit at 21 dBm, and the maximum power of the mobile device is 24 dBm, which results in a power headroom of 3 dB, and the maximum number of resource blocks that the mobile device can use would be 2, because adding two resource blocks requires twice the power, which adds an additional 3dB to the power.

Next, the process determines whether the mobile device resource usage limit exceeds a reporting threshold, as indicated at 512 . The reporting threshold may be set at a level that prevents mobile devices that are not limited by their power headroom from reporting mobile device power limitations. Mobiles that are not limited by their power headroom can reserve the bandwidth needed to report resource usage constraints because the scheduler in the base station (or base station controller) does not need to be concerned with Scheduling resources are limited. Conversely, if a mobile device is limited by its power headroom, the scheduler needs to know (preferably before scheduling) so that it will not schedule resource allocations that would exceed the mobile device's transmit power capacity.

If the resource usage limit exceeds the reporting threshold, the process enters 514, wherein the process sends a synchronous RACH (such as the synchronous RACH 214 shown in Figure 4) to the base station, wherein the synchronous RACH includes a resource allocation request and a resource usage limit. Resource allocation requests may include requests for file transfers, voice calls, video or music files, or the like. Resource usage restrictions may include a maximum number of resource blocks, a maximum level of modulation and coding, or other similar resource restrictions that depend on mobile device transmit power. Please note that in another embodiment, the resource usage limit parameter can be transmitted in a dedicated message, and does not have to be piggy-backed in a synchronous RACH message.

If the resource usage limit does not exceed the reporting threshold, the process proceeds to 516, where the mobile device sends a synchronous RACH to the base station including a resource allocation request but no resource usage limit.

After sending the synchronization RACH message to the base station, the process may receive a channel measurement command, as indicated at 518 . In response to the channel measurement command, the process sends a sequence of channel measurement data, as shown at 520 . A channel measurement data sequence is a known data sequence transmitted at a known transmit power on a preselected frequency across the communication system bandwidth. Channel measurements give base stations and/or base station controllers data indicative of channel quality at various frequencies across the frequency spectrum. This information is useful when scheduling uplink transmissions from mobile devices, since the scheduler is more willing to grant resources to mobile devices that are currently able to use those resources with the desired channel quality. In embodiments where the system does not use channel measurements, the base station 204 may infer the CINR from long-term tracking of the channel through reference symbols of the data channel.

After sending the channel measurement sequence, the process receives a dynamic or persistent resource allocation grant at 522 and determines whether the grant is dynamic or persistent. If the grant is dynamic, the process receives instructions for dynamic uplink transmission, including power control instructions for use during the duration of the dynamic resource grant, as indicated at 524 . The process then transmits in the uplink according to the dynamic resource allocation grant, as shown at 526, and uses power control instructions to set the transmit power for the duration of the grant. At the end of the data transfer granted under the dynamic resource allocation, the process ends, as shown at 536 .

Alternatively, if the grant is persistent, the process receives instructions for persistent uplink transmission, including an initial power control instruction to start transmission of the persistent resource grant, as indicated at 528 . The process then transmits in the uplink according to the persistent resource allocation grant and starts the persistent grant transmission using the initial power control command, as indicated at 530 . After a period of time, the process receives additional power control instructions, as indicated at 532 .

Next, the process determines whether the persistent authorization has expired, as indicated at 534 . If the persistent grant has not expired, the process continues to send more data at 530 and periodically receives updated power control instructions at 532 .

If the persistent grant has expired, the processing of transmissions on the allocated uplink resources according to the persistent resource grant ends, as shown at 536 .

FIG. 6 shows a high-level flowchart of processes that may be performed by mobile device 106 in FIG. 1 , or other systems with appropriate functionality, in accordance with one or more embodiments. As shown, the process begins at 602 and thereafter continues at 604, where the process receives cell-wide power control parameters. Cell-wide power control parameters are parameters sent by the serving base station to all mobile devices in the cell. This parameter may be sent through a broadcast channel. In one embodiment, the cell-wide power control parameter is a cell target value for a signal-to-interference-plus-noise ratio (SINR) received by a base station (eg, base station 102). In another embodiment, the cell-wide power control parameter may be a fractional power control index, shown as the symbol "α" in Equation 1 above.

After receiving the cell-wide power control parameters, the process determines implicit mobile-specific power control parameters related to the target received power of the serving base station, as indicated at 606 . Implicit mobile-specific power control parameters are parameters related to uplink power control specific to the mobile device (i.e. parameters not broadcast) and implied by other messages or commands sent to the mobile device, or made by the mobile device A measurement of , which enables the implicit parameters to require no additional message traffic from the base station. In one embodiment, the implicit mobile-specific power control parameter may be the modulation and coding level previously used by the mobile device. The modulation and coding level is sent by the base station to the mobile device, and it implicitly indicates the characteristics of the uplink channel between the mobile device and the base station. In one embodiment, the modulation and coding level previously used by the mobile device may be an average modulation and coding level averaged over time windows.

In another embodiment, the implicit mobile-specific power control parameter may be a downlink SINR level (or an average downlink SINR level) measured by the mobile device. In a time-domain duplex (TDD) communication system, according to the reciprocity principle, the downlink SINR implicitly indicates the uplink channel characteristics. In a Frequency Domain Duplex (FDD) communication system, the uplink and downlink channel fast fading components may not be correlated even though the path loss and shadowing effect components are the same. Averaging the downlink SINR over time and frequency will yield an average of the fading components and provide a good implicit estimate of the uplink channel characteristics.

In some embodiments, the mobile device may also receive mobile-specific power control parameters in addition to cell-wide power control parameters and implicit mobile-specific power control parameters. The mobile-specific power control parameters may be received in a message from the base station specific to the mobile device. In cases where the mobile device receives cell-wide power control parameters and mobile-specific power parameters, the implied mobile-specific power control parameters may be the association between the mobile-specific power control parameters and the modulation and coding level specified by the serving base station . Thus, the implicit mobile-specific power control parameters may vary between cases where the mobile-specific power control parameters are directly associated with the modulation and coding scheme and cases where the mobile-specific power control parameter is indirectly associated with the modulation and decoding scheme. As an example, a direct correlation between power control parameters and modulation and coding schemes is that mobile devices receive relatively high power and relatively high modulation and coding levels (i.e., modulation and coding levels that require higher power), and mobile devices receive A similar situation for relatively low power and relatively low modulation and coding levels. An example of an indirect correlation between a power control parameter and a modulation and coding scheme is that a mobile device receives relatively high power and a relatively low modulation and coding scheme, and vice versa. Thus, the implicit mobile-specific correlation coefficient varies between desired power levels and modulation and coding schemes and undesired combinations of power levels and modulation and coding schemes.

Next, the process uses the cell-wide power control parameters and the implicit mobile-specific power control parameters to calculate the uplink transmit power of the mobile device, as shown in 608 . In this step, the implicit mobile-specific power control parameters are used to adjust the transmitter power indicated by the cell-wide power control parameters, or to adjust the cell-wide power control parameters and the mobile-specific power control parameters transmit power. In one embodiment, the adjustment may be a percentage of transmit power indicated by a calculation using cell-wide parameters, or by a calculation using cell-wide parameters and mobile-specific parameters.

As an example, assume that a base station broadcasts a cell-wide target SINR mapped to an average MCS level (SINR ₁₆ ) of 16QAM (ie, 16 constellation points, quadrature amplitude modulation) with code rate 1/2. The mobile device will first calculate its transmit power to ensure that its signal received by the base station has a cell-wide target SINR ₁₆ . The mobile device can then autonomously calculate the correction coefficients based on implicit mobile-specific power control parameters such as the uplink MCS history assigned to the mobile device. If the mobile observes that its average MCS level assigned by time and frequency is 4QAM rate 1/2, which maps to the average received SINR at the base station is SINR ₄ , then the SINR ₁₆ -SINR ₁₄ can be applied autonomously by the mobile The coefficients are corrected to match the SINR ₁₆ that the base station expects to receive. Thus, the difference between the target SINR and the implied SINR determines plus (if the measured MCS implies a lower SINR at the base station) or minus (if the measured MCS implies a higher SINR at the base station) an autonomous correction coefficient.

In one embodiment, this difference (ie, correction factor) can be applied directly to the transmit power in one go. In another embodiment, either by applying a number of fixed correction increments (e.g., by 1 dB change), or by applying a correction factor percentage a fixed number of times (for example, by 20% of the correction factor over 5 changes) to change), the correction factor can be applied incrementally over a period of time. Correction coefficients may be calculated periodically even if previous correction coefficients were fully applied before.

Moreover, the mobile device can perform continuous measurement of the downlink SINR level and average the measured values according to time and frequency to estimate the long-term downlink received SINR. This estimated long-term SINR can then be compared to the uplink SINR expected by the mobile device based on the autonomously corrected transmit power calculated in the example above. A delta correction factor can be calculated and applied based on the difference, and can then be used in the calculation of the autonomous correction factor to increase its accuracy. The delta calibration coefficients can be used to compensate for errors in transmit power due to the difference between the set transmit power and the actual transmit power in the mobile device.

After calculating the uplink transmit power of the mobile device, the mobile device uses the transmit power to transmit data, as shown in 610 . Data is transmitted at the time and frequency indicated by the resource allocation grant. The process ends at 612 after data is transmitted using the calculated transmit power.

If the mobile device is granted a resource allocation that cannot be achieved in the transmission at 612 due to power constraints in the mobile device (e.g., the combination of transmit power and MCS cannot be achieved because the combination exceeds the maximum power of the mobile device), the mobile device There are multiple options: (1) the mobile device can transmit using lower power; (2) the mobile device can transmit using a lower MCS level; (3) the mobile device can transmit on a reduced number of resource blocks; (4) The mobile device may resend the request for resource allocation (e.g., resend the synchronous RACH message 214), wherein the resent request includes an indication (e.g., 308) of the resource usage limit that caused the previous grant to exceed the mobile device's power limit .

Although the present application has described the invention in conjunction with specific embodiments, various modifications and changes can be made without departing from the scope of the invention as described in the appended claims. For example, one or more embodiments may be used in a system operating in accordance with the 3GPP LTE standard, although techniques and means for controlling transmit power in a mobile device may vary widely. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive, and all such modifications are included within the scope of the present invention. Any benefits, advantages or solutions to problems described in this application with respect to particular embodiments are not intended to be construed as a key, required or essential feature or element of any or all of the claims.

Unless stated otherwise, terms such as "first" and "second" are used to arbitrarily distinguish between the elements such terms describe. Accordingly, these terms are not intended to indicate a temporal or other priority of these elements.

Claims (17)

1. method of controlling the transmitting power of mobile device comprises following steps:

Determine the resource use restriction of mobile device;

Determine described resource uses restriction whether to surpass the report threshold value;

Use restriction to surpass described report threshold value in response to described resource, use the message of restriction to be sent to the base station from described mobile device the described resource of indication;

Receive the mandate that resource is distributed; And

When the mandate of the resource distribution that receives surpasses the resource use restriction of described mobile device, use with the resource of the Grant for resource allocation that receives and compare, use the resource that reduces to make to launch, otherwise make to launch with regard to the resource of utilizing the Grant for resource allocation that receives.

2. the method for the transmitting power of control mobile device as claimed in claim 1, determine that wherein the resource of mobile device comprises with the step that limits the transmission power limit of determining described mobile device in response to current transmit power.

3. the method for the transmitting power of control mobile device as claimed in claim 1, determine that wherein the resource of mobile device uses the step of restriction to comprise the Resource Block restriction of definite described mobile device.

4. the method for the transmitting power of control mobile device as claimed in claim 1 is determined wherein that step that resource uses restriction whether to surpass the report threshold value comprises and is determined whether the power climbing space restriction surpasses the report threshold value.

5. the method for the transmitting power of control mobile device as claimed in claim 1 is determined wherein that step that resource uses restriction whether to surpass the report threshold value comprises and is determined whether the resource block capacity restriction surpasses the report threshold value.

6. the method for the transmitting power of control mobile device as claimed in claim 1, wherein will indicate described resource to use the message of restriction to comprise from the step that described mobile device is sent to the base station message that sends the described resource use of indication restriction in response to random access channel responses.

7. the method for the transmitting power of control mobile device as claimed in claim 1, wherein will indicate described resource to use the message of restriction to be included in from the step that described mobile device is sent to the base station message that sends the described resource use of indication restriction synchronous Random Access Channel message.

8. the method for the transmitting power of control mobile device as claimed in claim 1, wherein will indicate described resource to use the message of restriction to comprise from the step that described mobile device is sent to the base station message that sends the described resource use of indication restriction in response to Grant for resource allocation.

9. the method for the transmitting power of control mobile device as claimed in claim 1, wherein, the resource of described minimizing is used and is comprised according to described resource and use restriction to use the resource of lower-wattage to distribute.

10. the method for the transmitting power of control mobile device as claimed in claim 1, wherein, the resource of described minimizing is used and to be comprised according to described resource and use restriction to use and the modulation of authorizing and the lower modulation of encoding scheme phase specific capacity and the resource distribution of encoding scheme.

11. the method for the transmitting power of control mobile device as claimed in claim 1, wherein, the resource of described minimizing is used and to be comprised according to described resource and use restriction to use to compare with the resource block number of authorizing the number of resource blocks purpose resource of having reduced to distribute.

12. a method of controlling the power that mobile device launches comprises following steps:

Send resource allocation request to the base station from described mobile device;

Receive the Dynamic Resource Allocation for Multimedia mandate from described base station, wherein said Dynamic Resource Allocation for Multimedia mandate is included in the duration power control instruction that uses of Dynamic Resource Allocation for Multimedia mandate;

Distribute request to be sent to the base station from mobile device Secondary resource;

Receive Persistent resource allocation grant from described base station, wherein said Persistent resource allocation grant is included in the second power control instruction that initially uses during Persistent resource allocation grant; And

Described Persistent resource allocation grant the duration receive the subsequent power control command.

13. the method for the power that control mobile device as claimed in claim 12 is launched also comprises following steps:

Reception is from the channel measurement request of described base station; And

Launch the channel measurement data in response to described channel measurement request.

14. comprising, the method for the power that control mobile device as claimed in claim 12 is launched, the step that wherein receives the Dynamic Resource Allocation for Multimedia mandate receive the distribution that comprises a plurality of Resource Block and the Dynamic Resource Allocation for Multimedia mandate of using the instruction of dynamic authorization through-put power.

15. the method for the power that control mobile device as claimed in claim 12 is launched, the step that wherein receives the Dynamic Resource Allocation for Multimedia mandate comprises the dynamic resource mandate that reception is authorized the resource in the mobile device resource limitation, and wherein said mobile device resource limitation is relevant to the mobile device Power Limitation.

16. the method for the power that control mobile device as claimed in claim 14 is launched, the step that wherein receives the dynamic resource mandate comprises the dynamic resource mandate that reception is authorized the resource block number in the restriction of mobile device Resource Block, and wherein said mobile device Resource Block restriction is relevant to the mobile device margin of power.

17. the method for the power that control mobile device as claimed in claim 12 is launched, wherein Persistent resource allocation grant the duration receive the subsequent power control command step be included in described Persistent resource allocation grant the duration receive subsequent power and adjust instruction, wherein said subsequent power is adjusted in the instruction that instruction comprises the instruction that increases power and minimizing power.

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